My understanding is that `include` is like `template` but for file: in-place
code replacement, just like C `#include`. I broke my big file into small
includes, and now inapprehensible errors pop up... This example presents the
reverse of what I see with my code: big file compiling while includes don't.
**myinclude.nim**
type
A = object
str: string
template conc(s1: A, s2: string): string =
s1.str & s2
Run
**foo.nim**
template foo*(sFoo: untyped) =
block:
include myinclude
template bar(sBar: untyped) =
echo "In bar"
sBar
echo "In foo"
sFoo
echo "completed foo"
foo:
bar:
echo conc(A(str: "hello"), "world")
Run
This compiles and outputs
In foo
In bar
helloworld
completed foo
Run
Now, if instead of including the file, I copy its content replacing the
`include myinclude`, to get **foo.nim**
template foo*(sFoo: untyped) =
block:
type A = object
str: string
template conc(s1: A, s2: string): string =
s1.str & s2
template bar(sBar: untyped) =
echo "In bar"
sBar
echo "In foo"
sFoo
echo "completed foo"
foo:
bar:
echo conc(A(str: "hello"), "world")
Run
It does not compile anymore, with `Error: undeclared identifier: 'A'`
What does `include` do exactly?
_Also as a side note, if you don 't declare the type ``A``, Nim compiler
optimize the string concatenation and both versions compile..._
